Clean, Clean, Clean.
Wash down the ceiling and walls.
Wet the floor.
I used 2 box fans at the garage door.
Cut some plywood and place in between the fans to help get a good pull. Use a furnace filter in the window for the draw.
Paint will bounce off of plastic.
Using paper is better.
Then practice. Get your stokes even, going past the area to be painted. This way you will not double up on the paint getting near the ends